diff --git a/backend/src/services/user.rs b/backend/src/services/user.rs
index 4b295ec..89a51c5 100644
--- a/backend/src/services/user.rs
+++ b/backend/src/services/user.rs
@@ -368,7 +368,8 @@ pub async fn sign_in_post(
             Ok((
                 jar.add(cookie),
                 Redirect::to(&format!(
-                    "/?{}={}&{}={}",
+                    "/{}/?{}={}&{}={}",
+                    context.tr.current_lang_code(),
                     common::consts::GET_PARAMETER_USER_MESSAGE,
                     Sentence::SignInSuccess as i64,
                     common::consts::GET_PARAMETER_USER_MESSAGE_LEVEL,
@@ -394,7 +395,10 @@ pub async fn sign_out(
         jar = jar.remove(consts::COOKIE_AUTH_TOKEN_NAME);
         connection.sign_out(&token).await?;
     }
-    Ok((jar, Redirect::to("/")))
+    Ok((
+        jar,
+        Redirect::to(&format!("/{}/", context.tr.current_lang_code())),
+    ))
 }
 
 /// RESET PASSWORD ///
diff --git a/backend/tests/http.rs b/backend/tests/http.rs
index 11287bc..9d31fb6 100644
--- a/backend/tests/http.rs
+++ b/backend/tests/http.rs
@@ -219,7 +219,8 @@ async fn sign_in() -> Result<(), Box<dyn Error>> {
     response.assert_status_see_other(); // Redirection after successful sign in.
     response.assert_text("");
     // English is the default language.
-    response.assert_header("location", "/?user_message=16&user_message_icon=0");
+    response.assert_header("location", "/en/?user_message=16&user_message_icon=0");
+    dbg!(&response);
 
     Ok(())
 }